113,798 research outputs found
Study on the elastic-plastic behavior of a porous hierarchical bioscaffold used for bone regeneration
No full textA perfectly plastic von Mises model is proposed to study the elastic-plastic behavior of a porous hierarchical scaffold used for bone regeneration. The proposed constitutive model is implemented in a finite element (FE) routine to obtain the stress-strain relationship of a uniaxially loaded cube of the scaffold, whose constituent is considered to be composed of cortical bone. The results agree well with experimental data for uniaxial loading case of a cancellous bone. We find that the unhomogenized stress distribution results in different mechanical properties from but still comparable to our previous theory. The scaffold is a promising candidate for bone regeneration
INNOVATIVE PILLAR[6]ARENE-BASED STATIONARY PHASES FOR HIGH-RESOLUTION GAS CHROMATOGRAPHIC ANALYSES
No full textIn this work, the synthesis, fabrication, and characterization of new stationary phases based on pillar[6]arene derivative modified by long alkyl chains (P6A-C10) for high-resolution gas chromatographic (GC) analyses are reported. Pillar[n]arenes are a new class of macrocyclic hosts that can accommodate specific guests due to their highly symmetrical and rigid pillar architectures with π-electron rich cavities. Quantum chemistry calculations have been performed, showing a difference in non-covalent interactions with the P6A-C10 pillar framework, which leads to specific selectivity for aromatic compounds. The GC columns prepared with these innovative stationary phases exhibited a medium polarity, and good reproducibility for run-to-run, day-to-day, and column-to-column analyses [1], demonstrating great potential as new stationary phases in separation science. Furthermore, peculiar advantages are achieved if compared with the commercial HP-5, HP-35, DB-17, and PEG-20M columns, showing unmatched resolving capabilities toward chloroaniline, bromoaniline, iodoaniline, toluidine, and xylene isomers [2].
References:
1. Sun, T., Chen, R., Huang, Q., Ba, M., Cai, Z., Hu, S., Liu, X., Nardiello, D., & Quinto, M., ACS Appl. Mater. Interfaces 14 (2022) 56132−56142.
2. Sun, T., Chen, R., Huang, Q., Ba, M., Cai, Z., Chen, H., Qi, Y., Chen, H., Liu, X., Nardiello, D., & Quinto, M., Anal. Chim. Acta 1251 (2023) 340979
Cadmium and lead contamination of soils near plastic stabilizing materials producing plants in northern Taiwan.
No full textA generic postprocessing technique for image compression
No full textA postprocessing approach is developed for image coding applications. In this approach, a distortion-recovery model extracts multi-resolution edge features from the decompressed image and uses these visual features as input to estimate the difference image between the original uncompressed image and the decompressed image. Coding distortions are directly compensated by adding the model output to the decompressed image. Unlike the majority of existing postprocessing methods, which adopt filtering techniques to smooth blocking artifacts and are designed specifically for transform coding or vector quantization, the proposed approach is a generic postprocessing technique and can be applied to all of the main coding methods. Experiments involving postprocessing four coding systems were conducted, and the results obtained show that the proposed technique achieves significant improvements on the quality of reconstructed images, both in terms of the objective distortion measure and subjective visual assessment
Using visual feature extraction neural network model to improve performance of quadtree based image coding
No full textIn this paper, we propose a new technique to improve the performance of quadtree (QT) based image coding through the utilization of a neural network based visual feature extraction model(VFEM). After QT reconstruction is completed, a trained VFEM uses the information contained in the QT reconstructed image to recover the QT reconstruction error. This results in a better quality reconstructed image than the one simply reconstructed from QT representation. Since no extra information other than QT structure itself needs to be transmitted, the VFEM improvement does not increase the coding bit rate. Therefore, a better rate-distortion performance is achieved
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